The Influence of a Total Body Resistance Training Program on Autonomic Modulation and Strength Variables in Young Adults.

The purpose of this study was to examine autonomic modulation using multiple quantitative measures before and after a resistance training (RT) intervention. Seventeen young adults (age 18-35 years) were tested for body composition, muscular strength, and autonomic activity. The RT protocol targeted total-body large muscle groups, which were performed three days a week for eight-weeks. Autonomic assessments included respiratory sinus arrhythmia (RSA), static handgrip exercise, Valsalva maneuver, heart rate variability (HRV), and tilt-table testing. The main finding was that tilt-table duration increased by 68 seconds ( = 0.05) after RT. Upper body strength increased by 11.2 kg ( = 0.001) and lower body strength increased by 68.3 kg ( < 0.001) following completion of the RT intervention. The average total lean mass increased by 1.5 kg ( < 0.01), while total fat mass was unchanged (Δ = 0.5 kg, = 0.23). RSA (Δ = 0.4, = 0.89), Valsalva ratio (Δ = -0.09, = 0.48), static handgrip (Δ = 8 mm Hg, = 0.07), and HRV (Δ = -0.4, = 0.53) were not affected by RT. The results from this study suggest that RT improves tilt-table tolerance in a young healthy population as evidence by improved tilt-table duration. However, RT seemed to have no effect on cardio-vagal or adrenergic function.